We learn by connecting new information to prior knowledge (Palfreman, 1992). Much of this involves categorizing information according to patterns. Whereas the average American football fan just sees 11 individual defenders on the field, a veteran NFL quarterback sees the formation within the context of a category, such as a “two-deep zone.” This allows him to quickly interpret formations and decide how to react to them. In this way, much of expertise comes down to accumulating a storehouse of categories for structuring new information.